High-isolation circuit based on LTCC substrate

Abstract

The utility model discloses a high isolation circuit based on an LTCC substrate. The high isolation circuit comprises an LTCC substrate, a plurality of metal layers, a microwave radio frequency line I and a microwave radio frequency line II. The microwave radio frequency circuit I comprises a plurality of strip conductors and a radio frequency device I; the radio frequency device I is connected with the corresponding strip conductor; the microwave radio frequency line II comprises a plurality of strip conductors and a radio frequency device II; the radio frequency device II is connected with the corresponding strip conductor; the plurality of metal layers are sequentially arranged on the LTCC substrate from top to bottom in a layered manner; the strip-shaped conductor is embedded in the LTCC substrate, and the radio frequency device I and one metal layer are arranged on the same layer; a groove is formed in the top surface of the LTCC substrate to form a cavity, and the radio frequency device II is arranged in the cavity; the strip conductor of the microwave radio frequency line I, the radio frequency device I, the strip conductor of the microwave radio frequency line II and the radio frequency device II are located on different metal layers. According to the utility model, the size of the microwave radio frequency circuit can be reduced, and miniaturization and integration of the microwave radio frequency circuit are realized.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the microwave radio frequency circuit technical field, concretely relates to a high isolation degree circuit based on LTCC substrate. BACKGROUND

[0002] Under the rapid development of microwave wireless technology, communication system is developing towards miniaturization, integration and multifunction, and due to the demand of miniaturization, EMC (electromagnetic compatibility) design of circuit is particularly important, and isolation degree index requirement of radio frequency circuit channel is improved. In the traditional design method, the distance of two transmission lines is increased, and the isolation degree between the two transmission lines is increased, but this design will increase the circuit plane size, and the volume is large, which is not suitable for the miniaturization demand of microwave radio frequency circuit. UTILITARY MODEL CONTENT

[0003] Therefore, the utility model provides a high isolation degree circuit based on LTCC substrate, which is beneficial to improve the isolation degree between high integration circuit channels, can reduce the volume of microwave radio frequency circuit, and realizes the miniaturization and integration of microwave radio frequency circuit.

[0004] The utility model is realized through the following technical schemes:

[0005] A high isolation degree circuit based on LTCC circuit board, comprising: LTCC substrate, metal floor group and at least two microwave radio frequency lines;

[0006] Two microwave radio frequency lines are microwave radio frequency line I and microwave radio frequency line II respectively;

[0007] The microwave radio frequency line I includes a plurality of strip conductors and radio frequency devices I;Radio frequency device I and corresponding strip conductor are connected;

[0008] The microwave radio frequency line II includes a plurality of strip conductors and radio frequency devices II;Radio frequency device II and corresponding strip conductor are connected;

[0009] The metal floor group includes a plurality of metal layers, and the plurality of metal layers are sequentially layered on the LTCC substrate from top to bottom;

[0010] The strip conductor of microwave radio frequency line I is embedded in the LTCC substrate, and is in the same layer with at least one metal layer;Radio frequency device I is arranged in the same layer with one metal layer;

[0011] The strip conductor of microwave radio frequency line II is embedded in the LTCC substrate, and is in the same layer with at least one metal layer;The top surface of the LTCC substrate is provided with a groove, forming a cavity, and the radio frequency device II is arranged in the cavity, and the radio frequency device II is arranged in the same layer with one metal layer;

[0012] The strip conductor of microwave radio frequency circuit I, radio frequency device I, and the strip conductor and radio frequency device II of microwave radio frequency circuit II are located in different metal layers.

[0013] Furthermore, the metal ground plane assembly includes eight metal layers: a top printed metal ground plane located on the top layer of the LTCC substrate, a bottom printed metal ground plane located on the bottom layer of the LTCC substrate, and six embedded metal ground planes that are uniformly distributed from top to bottom within the LTCC substrate; the eight metal layers are connected by several metal ground vias.

[0014] Furthermore, the strip conductors of the aforementioned microwave radio frequency circuit I are strip conductor I and strip conductor II; both strip conductor I and strip conductor II are embedded in the LTCC substrate, and two through holes I are provided on the three-layer embedded metal floor. Strip conductor I and strip conductor II are respectively arranged in the two through holes I and are on the same layer as the three-layer embedded metal floor.

[0015] Radio frequency device I is located on the top layer of the LTCC substrate, on the same layer as the top printed metal ground plane;

[0016] The aforementioned microwave radio frequency circuit Ⅱ has strip conductors Ⅲ and Ⅳ. Both strip conductors Ⅲ and Ⅳ are embedded in the LTCC substrate. Two through holes Ⅱ are provided on the six-layer embedded metal floor. Strip conductors Ⅲ and Ⅳ are respectively installed in the two through holes Ⅱ and are on the same layer as the six-layer embedded metal floor.

[0017] Radio frequency device II is located inside the cavity and is on the same layer as the four-layer embedded metal ground plane.

[0018] Furthermore, microwave radio frequency circuit I also includes microstrip line I, microstrip line II, microstrip line III and microstrip line IV;

[0019] Microstrip line I, microstrip line II, microstrip line III and microstrip line IV are all located on the top layer of the LTCC substrate, on the same layer as the top printed metal ground plane;

[0020] Microstrip line I, strip conductor I, microstrip line II, radio frequency device I, microstrip line III, strip conductor II, and microstrip line IV are connected end to end in sequence; microstrip line I and strip conductor I, strip conductor I and microstrip line II, microstrip line III and strip conductor II, and strip conductor II and microstrip line IV are all connected through transmission line metallized interconnects; microstrip line II and radio frequency device I, and radio frequency device I and microstrip line III are all connected through metal bonding wires.

[0021] Furthermore, the microwave RF circuit II also includes microstrip line V, microstrip line VI, microstrip line VII and microstrip line VIII; microstrip line V and microstrip line VIII are both located on the top layer of the LTCC substrate and are on the same layer as the top printed metal ground plane; microstrip line VI and microstrip line VII are both located inside the cavity and are on the same layer as the four embedded metal ground planes;

[0022] Microstrip line V, strip conductor III, microstrip line VI, RF device II, microstrip line VII, strip conductor IV, and microstrip line VIII are connected end to end in sequence; microstrip line V and strip conductor III, strip conductor III and microstrip line VI, microstrip line VII and strip conductor IV, and strip conductor IV and microstrip line VIII are all connected through transmission line metallized interconnects; microstrip line VI and RF device II, and RF device II and microstrip line VII are all connected through metal bonding wires.

[0023] Furthermore, all microwave radio frequency lines are arranged in parallel.

[0024] Beneficial effects:

[0025] (1) The present invention provides a high isolation circuit based on LTCC circuit board. The top surface of the LTCC substrate is provided with a groove to form a cavity. The radio frequency device II is disposed in the cavity, so that the radio frequency device II and the strip conductor of microwave radio frequency line I, radio frequency device I and the strip conductor of microwave radio frequency line II are all located in different metal layers. The isolation of the integrated circuit is improved without increasing the circuit plane size, which is conducive to realizing the miniaturization of microwave radio frequency circuit.

[0026] (2) The present invention provides a high isolation circuit based on LTCC circuit board. By embedding the strip conductor inside the LTCC substrate, a highly integrated circuit design can be achieved, reducing external connections and components, thereby improving the compactness and reliability of the circuit. Furthermore, the design of the strip conductor and the embedded metal ground plane being on the same layer helps to reduce signal loss during signal transmission and improve signal transmission efficiency.

[0027] (3) The present invention provides a high isolation circuit based on LTCC circuit board. By placing the radio frequency devices in different metal layers, the mutual influence between different components can be reduced and the performance stability of the circuit under different working conditions can be improved. Attached Figure Description

[0028] Figure 1 This is a top view of a high-isolation circuit. Figure I ;

[0029] Figure 2 This is a top view of a high-isolation circuit. Figure II ;

[0030] Figure 3 yes Figure 2 AA section view;

[0031] Figure 4 yes Figure 2 BB cross-sectional view;

[0032] Figure 5 This is a schematic diagram of the first inner embedded layer;

[0033] Figure 6 This is a schematic diagram of the second inner embedded layer;

[0034] Figure 7 This is a schematic diagram of the third inner embedded layer;

[0035] Figure 8 This is a schematic diagram of the fourth inner embedded layer;

[0036] Figure 9 This is a schematic diagram of the fifth inner layer;

[0037] Figure 10 This is a schematic diagram of the sixth inner layer;

[0038] Figure 11 This is a schematic diagram of the underlying layer;

[0039] Among them, 1-Microwave RF line I, 2-Microwave RF line II, 21-Top printed metal ground plane, 22-Bottom printed metal ground plane, 31-Microstrip line I, 32-Microstrip line II, 33-Microstrip line III, 34-Microstrip line IV, 35-Microstrip line V, 36-Microstrip line VI, 37-Microstrip line VII, 38-Microstrip line VIII; 41-First-layer embedded metal ground plane, 42-Second-layer embedded metal ground plane, 43-Third-layer embedded metal ground plane, 44-Fourth-layer embedded metal ground plane, 45-Fifth-layer embedded metal ground plane, 46-Sixth-layer embedded metal ground plane, 51-Strip conductor I, 52-Strip conductor II, 53-Strip conductor III, 54-Strip conductor IV, 6-Transmission line metallized via, 7-Metallic ground via, 8-Metal bonding wire, 91-RF device I, 92-RF device II, 101-Cavity. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0041] This embodiment provides a high-isolation circuit based on an LTCC substrate. See attached diagram. Figure 1 and 2 It includes an LTCC (low-temperature co-fired) substrate, a metal ground plane assembly, and at least two microwave and radio frequency lines; all microwave and radio frequency lines are arranged in parallel.

[0042] The two microwave radio frequency lines are microwave radio frequency line I1 and microwave radio frequency line II2, respectively.

[0043] The microwave radio frequency circuit I1 includes several strip conductors and radio frequency device I91; the radio frequency device I91 and the corresponding strip conductors are connected.

[0044] Microwave radio frequency circuit II2 includes several strip conductors and radio frequency device II92; radio frequency device II92 and corresponding strip conductors are connected;

[0045] The metal floor assembly comprises several metal layers, which are sequentially layered from top to bottom on an LTCC (low-temperature co-fired) substrate.

[0046] The strip conductor of microwave radio frequency line I1 is embedded in the LTCC substrate and is on the same layer as at least one metal layer; radio frequency device I91 is disposed on the same layer as a metal layer.

[0047] The strip conductor of microwave radio frequency circuit II2 is embedded in the LTCC substrate and is on the same layer as at least one metal layer; the top surface of the LTCC substrate is provided with a groove to form a cavity 101, and radio frequency device II92 is disposed in the cavity 101 and is on the same layer as a metal layer.

[0048] The strip conductor of microwave radio frequency circuit I1 and radio frequency device I91, and the strip conductor of microwave radio frequency circuit II2 and radio frequency device II92 are located in different metal layers.

[0049] This embodiment provides a high isolation circuit based on an LTCC substrate. The top surface of the LTCC substrate has a groove to form a cavity 101. The radio frequency device II 92 is disposed in the cavity 101, so that the radio frequency device II 92, the strip conductor of microwave radio frequency line I1, the radio frequency device I 91, and the strip conductor of microwave radio frequency line II 2 are all located in different metal layers. This improves the isolation of the integrated circuit without increasing the circuit planar size, which is beneficial to the miniaturization of microwave radio frequency circuits.

[0050] See appendix Figures 2-11 The metal floor assembly comprises eight metal layers: a top printed metal floor 21 located on the top layer of the LTCC substrate, a bottom printed metal floor 22 located on the bottom layer of the LTCC substrate, and six embedded metal floors 41, 42, 43, 44, 45, and 46, which are uniformly distributed from top to bottom within the LTCC substrate. The eight metal layers are connected by several metal ground vias 7. The first embedded metal floor 41, the second embedded metal floor 42, the third embedded metal floor 43, the fourth embedded metal floor 44, the fifth embedded metal floor 45, and the sixth embedded metal floor 46 are all grid-type metal floors.

[0051] The microwave radio frequency circuit I1 also includes microstrip line I31, microstrip line II32, microstrip line III33 and microstrip line IV34; the strip conductors of the aforementioned microwave radio frequency circuit I1 are strip conductor I51 and strip conductor II52;

[0052] Microstrip line I 31, microstrip line II 32, microstrip line III 33 and microstrip line IV 34 are all located on the top layer of the LTCC substrate, on the same layer as the top printed metal ground plane 21;

[0053] Both strip conductor I 51 and strip conductor II 52 are embedded in the LTCC substrate. Two through holes I are provided on the three-layer embedded metal ground plane 43. Strip conductor I 51 and strip conductor II 52 are respectively disposed in the two through holes I and are on the same layer as the three-layer embedded metal ground plane 43. Strip conductor I 51, together with the first-layer embedded metal ground plane 41 and the three-layer embedded metal ground plane 43, form a strip line with an impedance of 50 ohms. Strip conductor II 52, together with the first-layer embedded metal ground plane 41 and the three-layer embedded metal ground plane 43, form a strip line with an impedance of 50 ohms.

[0054] Radio frequency device I91 is located on the top layer of the LTCC substrate, on the same layer as the top printed metal ground plane 21;

[0055] Microstrip line I 31, strip conductor I 51, microstrip line II 32, RF device I 91, microstrip line III 33, strip conductor II 52, and microstrip line IV 34 are connected end to end in sequence; microstrip line I 31 and strip conductor I 51, strip conductor I 51 and microstrip line II 32, microstrip line III 33 and strip conductor II 52, and strip conductor II 52 and microstrip line IV 34 are all connected through transmission line metallized interconnecting vias 6; microstrip line II 32 and RF device I 91, and RF device I 91 and microstrip line III 33 are all connected through metal bonding wires 8;

[0056] Microwave radio frequency circuit II2 also includes microstrip line V35, microstrip line VI36, microstrip line VII37 and microstrip line VIII38; the strip conductors of the aforementioned microwave radio frequency circuit II2 are strip conductor III53 and strip conductor IV54;

[0057] Microstrip line V35 and microstrip line VIII38 are both located on the top layer of the LTCC substrate, on the same layer as the top printed metal ground plane 21; microstrip line VI36, RF device II92 and microstrip line VII37 are all located inside cavity 101, and on the same layer as the four-layer embedded metal ground plane 44.

[0058] Both strip conductors III 53 and IV 54 are embedded within the LTCC substrate. Two through-holes II are provided on the six-layer embedded metal ground plane 46. Strip conductors III 53 and IV 54 are respectively disposed in the two through-holes II and are on the same layer as the six-layer embedded metal ground plane 46. Strip conductor III 53, together with the five-layer embedded metal ground plane 45 and the bottom printed metal ground plane 22, forms a strip line with an impedance of 50 ohms. Strip conductor II 52, together with the five-layer embedded metal ground plane 45 and the bottom printed metal ground plane 22, forms a strip line with an impedance of 50 ohms.

[0059] Microstrip line V35, strip conductor III53, microstrip line VI36, RF device II92, microstrip line VII37, strip conductor IV54, and microstrip line VIII38 are connected end to end in sequence; microstrip line V35 and strip conductor III53, strip conductor III53 and microstrip line VI36, microstrip line VII37 and strip conductor IV54, and strip conductor IV54 and microstrip line VIII38 are all connected through transmission line metallized interconnecting vias 6; microstrip line VI36 and RF device II92, and RF device II92 and microstrip line VII37 are all connected through metal bonding wires 8.

[0060] The microstrip lines (microstrip line I 31, microstrip line II 32, microstrip line III 33, microstrip line IV 34, microstrip line V 35 and microstrip line VIII 38) located on the top layer of the LTCC substrate each form a corresponding 50-ohm microstrip line with the top printed metal ground 21 and the first layer of embedded metal ground 41, respectively; the microstrip lines (microstrip line VI 36 and microstrip line VII 37) located in the cavity 101 of the LTCC substrate each form a corresponding 50-ohm microstrip line with the fourth layer of embedded metal ground and the fifth layer of embedded metal ground, respectively.

[0061] Working principle:

[0062] The top surface of the LTCC substrate has a groove to form a cavity 101. The radio frequency device II 92 is disposed in the cavity 101, so that the radio frequency device II 92, the strip conductor of microwave radio frequency line I1, the radio frequency device I 91, and the strip conductor of microwave radio frequency line II 2 are all located in different metal layers.

[0063] When testing the isolation, a test fixture is connected to the bottom printed metal ground plane 22. The test fixture is a metal device with an RF connector. The circuit isolation of the high isolation circuit based on the LTCC substrate is measured to be greater than the isolation of microwave RF line I1 and microwave RF line II2 located on the same layer at the same distance. Therefore, the high isolation circuit based on the LTCC substrate in this embodiment improves the isolation of the integrated circuit without increasing the circuit plane size, which is beneficial to the miniaturization and integration of microwave RF circuits.

[0064] In summary, the above are merely preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A high isolation circuit based on an LTCC substrate, characterized in that The application relates to a high-isolation-degree circuit based on an LTCC substrate. The high-isolation-degree circuit based on the LTCC substrate comprises an LTCC substrate, a metal floor group and at least two microwave radio frequency lines. The two microwave radio frequency lines are microwave radio frequency line I and microwave radio frequency line II respectively. The microwave radio frequency line I comprises a plurality of strip conductors and a radio frequency device I; the radio frequency device I is connected with the corresponding strip conductor. The microwave radio frequency line II comprises a plurality of strip conductors and a radio frequency device II; the radio frequency device II is connected with the corresponding strip conductor. The metal floor group comprises a plurality of metal layers; the plurality of metal layers are sequentially arranged on the LTCC substrate from top to bottom. The strip conductor of the microwave radio frequency line I is embedded in the LTCC substrate and is in the same layer as at least one metal layer. The radio frequency device I is arranged in the same layer as one metal layer. The strip conductor of the microwave radio frequency line II is embedded in the LTCC substrate and is in the same layer as at least one metal layer; the top surface of the LTCC substrate is provided with a groove to form a cavity; the radio frequency device II is arranged in the cavity and is arranged in the same layer as one metal layer. The strip conductor of the microwave radio frequency line I, the radio frequency device I, the strip conductor of the microwave radio frequency line II and the radio frequency device II are arranged in different metal layers.

2. A high isolation circuit based on LTCC substrate as claimed in claim 1, wherein, The metal floor group comprises eight metal layers, which are a top layer printed metal floor arranged on the top layer of the LTCC substrate, a bottom layer printed metal floor arranged on the bottom layer of the LTCC substrate and a one-layer embedded metal floor, a two-layer embedded metal floor, a three-layer embedded metal floor, a four-layer embedded metal floor, a five-layer embedded metal floor and a six-layer embedded metal floor which are sequentially and evenly arranged in the LTCC substrate from top to bottom. The eight metal layers are connected through a plurality of metal floor vias.

3. The high-isolation-degree circuit based on the LTCC substrate according to claim 2, wherein the strip conductor of the microwave radio frequency line I is strip conductor I and strip conductor II; the strip conductor I and the strip conductor II are both embedded in the LTCC substrate; two through holes I are arranged on the three-layer embedded metal floor; the strip conductor I and the strip conductor II are arranged in the two through holes I one by one and are in the same layer as the three-layer embedded metal floor; The radio frequency device I is arranged on the top layer of the LTCC substrate and is in the same layer as the top layer printed metal floor. The strip conductor of the microwave radio frequency line II is strip conductor III and strip conductor IV; the strip conductor III and the strip conductor IV are both embedded in the LTCC substrate; two through holes II are arranged on the six-layer embedded metal floor; the strip conductor III and the strip conductor IV are arranged in the two through holes II one by one and are in the same layer as the six-layer embedded metal floor; The radio frequency device II is arranged in the cavity and is in the same layer as the four-layer embedded metal floor. The microwave radio frequency line I further comprises microstrip line I, microstrip line II, microstrip line III and microstrip line IV.

4. The high isolation circuit based on LTCC substrate as claimed in claim 3, wherein, The microstrip line I, the microstrip line II, the microstrip line III and the microstrip line IV are all arranged on the top layer of the LTCC substrate and are in the same layer as the top layer printed metal floor. The microstrip line I, the strip conductor I, the microstrip line II, the radio frequency device I, the microstrip line III, the strip conductor II and the microstrip line IV are sequentially and circularly connected. ​ The transmission line metallization communication hole connects between the microstrip line I and the strip conductor I, between the strip conductor I and the microstrip line II, between the microstrip line III and the strip conductor II, and between the strip conductor II and the microstrip line IV; the metal bonding wire connects between the microstrip line II and the radio frequency device I, and between the radio frequency device I and the microstrip line III.

5. A high isolation circuit based on LTCC substrate according to claim 3 or 4, characterized in that, The microwave radio frequency circuit II further comprises a microstrip line V, a microstrip line VI, a microstrip line VII and a microstrip line VIII; the microstrip line V and the microstrip line VIII are located on the top layer of the LTCC substrate, and are in the same layer with the top layer printed metal floor; The microstrip line VI and the microstrip line VII are located in the cavity, and are in the same layer with the four-layer embedded metal floor; The microstrip line V, the strip conductor III, the microstrip line VI, the radio frequency device II, the microstrip line VII, the strip conductor IV and the microstrip line VIII are sequentially connected in a head-to-tail manner; The transmission line metallization communication hole connects between the microstrip line V and the strip conductor III, between the strip conductor III and the microstrip line VI, between the microstrip line VII and the strip conductor IV, and between the strip conductor IV and the microstrip line VIII; the metal bonding wire connects between the microstrip line VI and the radio frequency device II, and between the radio frequency device II and the microstrip line VII.

6. A high isolation circuit based on LTCC substrate as claimed in claim 5, wherein, All the microwave radio frequency circuits are arranged side by side.

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